Chapter 4 Ecosystems and Communities

 Weather:  Is the day-to-day conditions of Earth’s atmosphere.  Climate:  Average conditions over a long period of time.  What is the climate and weather of Southern California? 4.1 Climate

 All the carbon dioxide builds up in the Earth’s atmosphere, trapping heat.  Greenhouse effect:  Natural process that stops all sun’s heat from escaping rapidly back to space.  Without the green house effect the Earth would be 30 C cooler. Solar Energy and the Greenhouse Effect

 The Earth’s surface can be divided into different temperate zones based on lines of latitude.  We have 3 different zones….

 Tropics:  Warmest temperature zone  Polar zones:  Coldest temperature zone  Temperate zone:  Seasonal changes.

What zone do we live in?  Temperate zone

 Why does a crab live in the ocean?  Why does a lion live in the Savanna?  They are all adapted to live in certain places.  Tolerance:  The ability to survive and reproduce under a range of environmental circumstances. 4.2 Niches and Community Interactions

 Habitat:  General place where an organism lives.

 Niche:  Describes not only what an organism does, but also how it interacts with biotic and abiotic factors in the environment.  It’s an organisms job.  Resources:  Any necessity of life, such as water, nutrients, light, food, or space. Niche

 What is a plant’s niche?  Photosynthesis and give us oxygen.  What is your niche?  Get good grades…etc

 If two people want the same job, what happens?  If there is limited food, what will the two species do?  Compete!

 Competitive exclusion:  If two species are similar in their requirements that the same resource limits both species growth, one species may succeed over the other.

 Predation:  An interaction in which one animal (the predator) captures and feeds on another animal (the prey).  Herbivory:  An interaction in which one animal (the herbivore) feeds on producers (such as plants). Predation, Herbivory, and Keystone Species

 We have a food chain with sea otters, sea urchins, and kelp. What would happen to the environment if the sea otters died off?  Sea urchin population would increase, while the kelp would decrease.

 The sea otter would be considered the keystone specie.  Keystone specie:  Can cause dramatic changes in the structure of a community.

Symbiosis What kind of people do you interact with?  Friends  Parents  Teammates  Teachers  Coaches  Boyfriend/Girlfriend

What kind of relationships do you have with them?

Story  In terms of Gary and I, what kind of relationship did we have?  +,--  In terms of Nicole and I, what kind of relationship do we have? +,++,+

What kind of relationship do these organisms have?  Human  ___  Mosquito ++

What kind of relationship do these organisms have?  Black billed Magpie ++  American Bison ++

Why does the tortoise have a neutral relationship while the rodent and frog are positive?  Gopher Tortoise 00  Rodent ++  Frog ++

 These reflect different levels of symbiosis.  Symbiosis:  When two species live closely together.  There are three main classes of symbiotic relationships.  Mutualism  Parasitism  Commensalism

Symbiotic Relationships  Parasitism:  One organisms benefits, other is harmed.  Mutualism:  Both organisms benefit  Commensalism:  One organisms benefits, the other is neither harmed or benefited

Parasitism

Commensalism

Mutualism

4.3 Succession  Ecological Succession:  Series of more-or-less predictable changes that occur in a community over time.  Ecosystems change over time, especially after disturbances, as some species die out and new species move in.

 Primary succession:  Area with no remnants of an older community.  Pioneer species:  The first species to colonize barren areas.  Secondary succession:  When disturbances damages an existing community but leaves soil intact.

Primary Succession

Succession

Secondary Succession 1 Year

Secondary Succession 5 years

Secondary Succession 10 years

Secondary Succession 25 years

Secondary Succession 30 years

Human Caused Disturbances  What is happening to trees and forests?  Deforestation:  Clearing of forests for agriculture.

 What do you think about when you hear California?  What do you think about when you hear Antarctica? 4.4 Biomes

 Biomes:  Defined by abiotic factors like climate and soil type, and biotic factors like plant and animal life.

 Tropical Rainforest  Tropical Dry Forest  Tropical Grassland/Savanna/Shrubland  Desert  Temperate Grassland  Temperate Woodland and Shrubland  Temperate Forest  Northwestern Coniferous Forest  Boreal Forest  Tundra Examples of Biomes

 Warm temperatures, has the most biodiversity and rainfall.  Tall trees form a dense, leafy covering called the canopy.  Shorter trees form the understory. Tropical Rainforest

 Warm; seasonal rainfall; compact soils; frequent fires set by lightning.  Migratory animals such as rhinos and elephants. Tropical Grassland/Savanna/Shrubland

 Least amount of precipitation.  Undergo extreme daily temperature changes. Hot and cold.  Cacti are adapted to store water. Desert

 Fertile soils, warm and hot summers, cold winters, and occasional fires. Temperate Grassland

 Deciduous trees:  Plants that shed their leaves during a particular season.  Coniferous trees:  Produce seed-bearing cones.  Cold winters, warm summers, year round precipitation. Temperate Forest

 Dense coniferous forests, winters are bitterly cold. Boreal Forest (Taiga)

 Permafrost:  Permanently frozen subsoil.  Strong winds, low precipitation, long cold dark winters.  Not a lot of biodiversity Tundra

 What factors affect life in aquatic ecosystems?  Water depth  Temperature  Flow  Amount of dissolved nutrients 4.5 Aquatic Ecosystems

 Who has been to the beach?  What happens to the water color when you get step out to the ocean?

 Light areas (photic zone)= light penetrates the water  Dark areas (aphotic zone) = limited light Water Depth

 Can plants live in the aphotic zone?  No, they cannot photosynthesize.  Benthos:  Organisms that live in the benthic (shallow) zone.

Deep Sea Creatures

 Can be divided into three main categories  1. Rivers and Streams  2. Lakes an Ponds  3. Freshwater Wetlands Freshwater Ecosystems

 Originate from underground water sources in mountains or hills.  Many animals depend on rivers and streams for food. Rivers and Streams

 Food webs in lakes and ponds often are based on a combination of plankton and attached algae and plants.  Plankton:  Includes phytoplankton (plant) and zooplankton (animal). Lakes and Ponds

 Wetlands:  Is an ecosystem in which water either covers the soil or is present at or near the surface for at least part of the year.  Nutrient rich, highly productive, and serve as breeding grounds for many organisms.  Purify water by filtering pollutants and help prevent flooding. Freshwater Wetlands

Estuaries  Estuaries:  Streams and rivers merge with an ocean.  Chesapeake bay!

 Serve as spawning and nursery grounds for many ecologically and commercially important fish and shellfish. Estuaries

 Ecologists divide the ocean into three zones based on depth and distance from shore. Marine Ecosystems

Ocean zones  Intertidal zone:  Area of shore between the high-tide and low-tide lines. Exposed to sun. (closest to land)  Coastal zone:  Low-tide out the edge of continental shelf. Some sunlight. (in between ocean and land)  Open Ocean zone:  90% of the world ocean area. Filled with zooplankton. (farthest away from land)